JP3026824B2 - Aspherical lens manufacturing equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an apparatus for manufacturing an optical lens such as a contact lens and an intraocular lens having an aspherical shape such as a toric shape, a bifocal shape, and a prism shape.

2. Description of the Related Art Conventionally, in the field of optics, particularly in the field of ophthalmic lenses in ophthalmology, in addition to simple spherical lenses, contact lenses for correcting astigmatism and the like have aspherical shapes such as toric shapes, bifocal shapes, and prism shapes. There is a demand for shaped optical lenses.

By the way, various methods for manufacturing such an aspherical lens have been conventionally proposed. For example, Japanese Patent Publication No. 63-12742 discloses that a roughly cut lens material is compressed (curved) in a radial direction. Under the deformed state, a method of manufacturing a toric lens by cutting the surface into a spherical shape with a cutting bit while rotating the lens material about one axis has been proposed.
JP-A-63-27813 discloses a bifocal shape by rotating a lens material around a plurality of rotation axes and cutting the surface around each rotation axis into a spherical shape with a cutting tool. Techniques for manufacturing lenses have been proposed.

However, in the former method disclosed in Japanese Patent Publication No. 63-12742, the lens material is forcibly deformed, so that the lens material is adversely affected by distortion and the like, and a good quality lens product is obtained. In the latter method disclosed in JP-A-63-27813, it is extremely difficult to control the change of the rotation axis of the lens material with high accuracy. Because of the difficulty, there is a large variation in the final lens shape, and there is a problem that it is difficult to stably obtain a lens product having required optical characteristics.

Also, in U.S. Pat.No. 4,884,482, a predetermined cutting tool is brought into contact with the lens material while rotating the lens material about one axis by a rotating member holding the predetermined lens material, and rotating the lens material. When the surface of the lens material is cut into a desired shape by rotating and rotating about one axis perpendicular to the rotation axis of the member, the rotation angle of the rotation member and the rotation angle of the cutting tool are detected, and the rotation member is detected. In synchronization with the rotation angle of the rotating member,
There has been proposed a method of manufacturing an aspherical lens in which the cutting tool is reciprocated in the approaching / separating direction by a predetermined amount according to the turning angle of the cutting tool.

However, to obtain an economical cutting speed of the lens material with a cutting tool, the rotating member must be at least 1000
Since it is necessary to rotate at a speed of more than 3,000 rotations / minute, preferably at least 3,000 rotations / minute, for example, when manufacturing a toric lens, the rotating member must be reciprocated at a speed of more than 2,000 times / minute. However, in order to reciprocate the rotating member provided with the rotary drive mechanism at such a high speed, a driving device having an extremely large output is required, and the control thereof is extremely difficult. Because vibration around the axis due to rotation is easily amplified due to rotation and accurate control is difficult, sufficient productivity cannot be obtained by such a method of manufacturing an aspheric lens, and its practical use is extremely difficult. There was.

(Problem to be Solved) Here, the present invention has been made in view of the above-mentioned circumstances, and a problem to be solved is to provide a high-quality aspherical lens without distortion or the like to obtain excellent quality stability. Another object of the present invention is to realize an aspherical lens manufacturing apparatus which can be manufactured with excellent productivity.

(Solution) In order to solve this problem, in the present invention, while rotating a predetermined lens material around one axis,
A predetermined cutting tool is brought into contact with the lens material, and is swiveled about one axis perpendicular to the rotation axis of the lens material. In the part, by cutting with different radii of curvature, to an apparatus for manufacturing an aspheric lens having a desired aspheric shape,
(A) a rotation member provided with a holder for holding the lens material and rotatably supported so that the lens material can rotate around one axis; and (b) rotation driving means for rotating the rotation member. (C) a rotation angle detecting means for detecting a rotation angle of the rotation member, and (d) a cutting bite disposed to face a holder of the rotation member and cutting a lens material held by the holder. A tool support member for supporting the tool so as to be able to pivot about one axis orthogonal to the rotation axis of the rotating member and to be able to reciprocate in the approaching / separating direction with respect to the lens material; Turning drive means for driving the member to turn,
(F) revolving angle detecting means for detecting the revolving angle of the bite supporting member; (g) reciprocating driving means for reciprocatingly driving the bite supporting member; and (h) detecting the position of the bite supporting member in the reciprocating direction. Reciprocating position detecting means,
(I) In synchronization with the rotation angle of the rotating member detected by the rotation angle detecting means, the bite supporting member by a predetermined amount corresponding to the turning angle of the bite supporting member detected by the turning angle detecting means. And control means for controlling the reciprocating drive means so that the reciprocating drive means can be reciprocated. The first reciprocal position detecting means for directly detecting the amount of operation in the reciprocal drive means And second reciprocating position detecting means for directly detecting the amount of movement of the bite supporting member, wherein the control means detects the turning angle based on a detection signal from the first reciprocating position detecting means. The amount of operation of the reciprocating drive means is determined according to the turning angle of the bite support member detected by the means, and the second reciprocating position detecting means is determined. Based on the detection signal by the apparatus for manufacturing a non-spherical lens, characterized in that the actuation amount of the reciprocating drive means so that feedback control is for its features.

(Operation / Effect) That is, according to the present invention, the cutting tool for cutting the lens material is synchronized with the rotation angle of the lens material, and a predetermined amount corresponding to the turning angle of the cutting tool is applied to the lens material. By being reciprocated in the approaching / separating direction with respect to the lens material, the lens material can be cut with different radii of curvature from each other in the circumferential direction and the radial direction.

Therefore, according to the present invention, various aspherical lenses can be manufactured without bending the lens material or changing the rotation center axis of the lens material. Since the control of the radius of curvature of the lens is performed by reciprocating the cutting tool side (the tool supporting member side) where the movement is gentle without moving the lens material side (the rotating member side) which is rotated at a high speed, The control of the radius of curvature of such a lens can be performed with a simple structure and with high accuracy, and its practical application can be advantageously achieved.

(Example) Hereinafter, in order to clarify the present invention more specifically, an example of the present invention will be described in detail with reference to the drawings. In this embodiment, a specific example of an apparatus for manufacturing an aspheric lens having a structure according to the present invention will be described, and a method for manufacturing an aspheric lens according to the present invention using the apparatus for manufacturing an aspheric lens will be described. A specific example will be described.

First, FIG. 1 shows a schematic configuration of an apparatus for manufacturing an aspherical lens having a structure according to the present invention. That is, the apparatus for manufacturing an aspherical lens according to the present embodiment is configured by the rotational motion performing unit 10 and the reciprocating motion performing unit 12.

In such a rotating motion performing unit 10, the main body 22 provided on the base 20 allows the rotating shaft 16 as a rotating member to be rotated.
It is supported rotatably about the axis and immovable in the direction of the axis and the direction perpendicular to the axis. And, the rotating shaft 16 is
A rotation drive motor 18 as a rotation drive means is driven to rotate around the rotation center (axial center) 14. A chuck 24 is provided at one end of the rotating shaft 16 in the axial direction, and the chuck 24 fixedly holds a lens material 26 as an object to be cut.

Further, the rotating motion performing unit 10 includes a rotation angle detecting device 28 for detecting a rotation angle of the rotating shaft 16.
In this embodiment, as shown in FIG. 2 and FIG. 3, the rotation angle detection device 28 is fixed to the rotation shaft 16 driven by the rotation drive motor 18, as shown in FIGS.
A disk 30 in which a number of slits 29 are formed at equal angular intervals in the outer peripheral portion, and a light source 32 such as a light emitting diode and a photoelectric element 34 such as a photodiode disposed on both sides of the disk 30 respectively. , A so-called photoelectric rotation sensor is used. In FIG. 3, 33
Is a lens for converting light from the light source 32 into parallel rays. That is, according to such a rotation angle detection device 28, as is well known, the light from the light source 32 transmitted through the slit 29 provided in the disc 30 causes the photoelectric element 34 to generate a phase difference of 1/4 cycle. Are detected, and these sine wave signals are subjected to waveform processing to obtain a pulse signal. Based on the pulse signal, the rotation angle (position) and the rotation angle (position) of the rotation shaft 16 are determined. The direction of rotation can be detected.

On the other hand, in the reciprocating motion executing section 12, as shown in FIG. 1, a base arranged opposite to the base 20 of the rotating motion executing section 10 at a predetermined distance. A swivel table 40 is provided for the table 36, and the rotary motion
Are supported so as to be rotatable around a rotation center 42 orthogonal to the rotation center 14 of the rotation shaft 16. Note that, in the swivel table 40 in the present embodiment, a bite support table 48 described later is used.
A guide rail (not shown) that guides the user from the position extending in parallel with the rotation center 14 of the rotation shaft 16 in the rotation movement performing unit 10 so as to swing his or her head by approximately 90 degrees on both sides in a total range of 180 degrees. The turning angle is set.

The turning table 40 is driven to turn around a turning center 42 by a turning drive motor 44 as turning drive means, and the turning angle (position) is detected by a turning angle detecting device 46. It is supposed to be. In addition, as the turning angle detecting device 46, a photoelectric type rotation sensor or the like similar to the rotating angle detecting device 28 is preferably used.

Further, a cutting tool support 48 is mounted on the revolving base 40, and is supported by a guide rail (not shown) so as to be able to reciprocate a predetermined distance in one direction orthogonal to the revolving center 42. And such a tool support table 48
Is reciprocally driven along a guide rail via a worm gear mechanism or the like by a reciprocating drive motor 50 as reciprocating drive means, and the position in the reciprocating direction is determined by a reciprocating position detecting means. The position is detected by one reciprocating position detecting device 52.
As the first reciprocating position detecting device 52, one that directly detects the amount of rotation of the rotating shaft of the reciprocating drive motor 50 and indirectly detects the reciprocating position of the cutting tool support 48 from the amount of rotation is used. That is, for example, a photoelectric rotation sensor or the like similar to the rotation angle detection device 28 is preferably used.

In addition, in the reciprocating motion execution unit 12 in the present embodiment, as the reciprocating position detecting means for detecting the reciprocating position of the bite support 48, the bite support is used based on the rotation amount of the rotating shaft of the reciprocating drive motor 50 as described above. In addition to the first reciprocating position detecting device 52 for indirectly detecting the reciprocating position of the tool 48, the bite support 48
A second reciprocating position detecting device 56 which is mounted between the turning table 40 and the turning table 40 and directly detects a relative movement amount of the cutting tool supporting table 48 with respect to the turning table 40. In this embodiment,
As the second reciprocating position detecting device 56, as shown in FIG. 4, a large number of slits 62 fixed to the cutting tool support 48 and formed in the moving direction of the cutting tool support 48 at equal intervals are formed. And a detector 60 having a light source and a photoelectric element (not shown) fixed to the swivel 40 and positioned on both sides of the rectangular plate 58. A so-called linear type photoelectric sensor is used. Then, similar to the photoelectric rotation sensor used as the rotation angle detection device 28 and the like, the turning of the bite support 48 is performed based on a pulse signal obtained by subjecting a sine wave signal detected by the detector 60 to waveform processing. The reciprocating position with respect to the table 40 can be directly detected.

Furthermore, as described above, the pivot 36
A cutting tool 54 is fixed by a tool holder 53 to a tool support 48 that is supported so as to be able to turn around and reciprocally move in the longitudinal direction of a guide rail extending perpendicular to the center 42 of rotation. It is mounted on.

Then, the cutting edge of the cutting tool 54 is opposed to the lens material 26 held by the chuck 24 provided on the rotating shaft 16 of the rotating motion performing unit 10 on the rotation center 14 of the rotating shaft 16. The cutting tool 54 is disposed in such a state that it can be squeezed.
The cutting edge of the cutting tool 54 can be moved toward and away from the lens material 26, and the cutting edge of the cutting tool 54 can be
The lens material 26 can be displaced in a direction perpendicular to the axis (radial direction).

Therefore, according to such an apparatus, as shown modelly in FIG. 5, the lens material 26 held by the rotating shaft 16 in the rotating motion performing unit 10 is caused to rotate around the rotation center 14. The cutting tool 54 supported by the cutting tool support 48 in the reciprocating motion performing section 12 is rotated around the center of rotation 42 while being in contact with the lens material 26, so that the lens is rotated by the cutting tool 54. The concave side of the material 26 can be cut over the entire surface.
By moving the cutting tool 54 in the direction of approaching / separating from the lens material 26 so that the tip of the lens can move on a locus along the target lens shape, a lens having a target curved surface shape Can be formed by cutting.

More specifically, in the apparatus of the present embodiment, as shown in FIG. 6, a target lens is supplied from an external input device 66 to a control device 64 of a reciprocating drive motor 50 for driving the cutting tool support 48. While the shape data is input, a rotation angle signal of the rotation shaft 16 that holds the lens material 26 detected by the rotation angle detection device 28, a cutting tool 54 that supports the cutting tool 54 detected by the turning angle detection device 46 A turning angle signal of the support table 48 and a reciprocating position signal of the cutting tool support table 48 supporting the cutting tool 54 detected by the first reciprocating position detecting device 52 are input.

Then, the control device 64 generates a lens material based on the rotation angle signal of the rotating shaft 16 input from the rotation angle detection device 28 and the turning angle signal of the bite support 48 input from the turning angle detection device 46. Cutting tool on 26
An abutment portion of 54 is obtained, and further, based on input data from the external input device 66, an amount by which the lens material should be cut at the abutment portion to give a target lens shape, that is, a cutting tool 54 is supported. Tool holder 48 and lens material
26, while the obtained target distance is obtained by the position signal of the byte support 48 input from the first reciprocating position detecting device 52.
The current distance between the lens material 26 and the current distance between the lens material 26 is compared with the current distance, and a signal for driving the bite support base 48 toward and away from the lens material 26 by an amount corresponding to the difference therebetween is transmitted to the reciprocating drive motor 50. Is output.

Further, in the control mechanism of the present embodiment, the reciprocating drive motor 50 is operated based on the output signal from the control device 64 of the reciprocating drive motor, so that the bite support 48
Is reciprocated, the actual amount of movement of the bite support 48 is detected by the second reciprocating position detecting device 56, and a signal thereof is input to the reciprocating drive motor control device 64. It has become. Then, the actual amount of movement of the bite support 48 input from the second reciprocating position detecting device 56 moves the bite support 48 obtained by the reciprocating drive motor control device 64 as described above. The feedback control for correcting the error amount is performed by comparison with the target movement amount to be performed.

In such a control mechanism, the rotation amount of the reciprocating drive motor 50 is directly detected as the first reciprocating position detecting device 52 for determining the target value of the moving amount of the bite support 48. Since a structure having such a structure is used, the reciprocating movement control of the tool support 48 can be performed with an excellent response speed following changes in the rotation angle and the like of the rotating shaft 16, and the tool support Second reciprocating position detecting device for feedback controlling the moving amount of the table 48
Since a structure that directly detects the moving amount of the tool support 48 is used as 56, the tool support 48 is used.
The feedback control of the amount of reciprocation can be performed with high accuracy.

More specifically, the first meridians (a-m) which are orthogonal to each other as shown in FIG.
c) In the 70 direction and the second meridian (bd) 72 direction,
When manufacturing a so-called toric aspherical lens 68 in which different radii of curvature (R1, R2) are set, as schematically shown in FIGS. 8 (a) to (d),
When the contact portion of the cutting tool 54 with the lens material 26 comes on the first meridian 70, the cutting tool 54 is positioned so as to be positioned on a locus providing a radius of curvature of R1 in the direction of the first meridian 70. The distance: l1 between the turning center 42 of the cutting tool support 48 supporting the tool 54 and the lens material 26 is determined according to the turning angle θ of the cutting tool support 48, while the cutting tool 54 for the lens material 26 is determined. Is the second meridian
72, the turning center 42 of the cutting tool support table 48 supporting the cutting tool 54 and the lens material so that the cutting tool 54 is positioned on the locus giving the radius of curvature of R2 in the direction of the second meridian 72. 26 is determined according to the turning angle θ of the cutting tool support 48.

In other words, a tool support 48 that supports the cutting tool 54
Is synchronized with the rotation angle of the lens material 26 rotated about the rotation center 14, and in a relationship of two reciprocations per one rotation of the lens material 26, a straight line parallel to the rotation center 14 is moved to the bite support 48. Is reciprocated by a predetermined amount in accordance with the turning angle around the turning center 42 of. Also, as shown in FIG. 8 (e), at the rotation position of the lens material 26 where the cutting bite 54 comes into contact between the first and second meridians 70 and 72 in the lens material 26. Is the distance between the turning center 42 of the cutting tool support 48 and the lens material 26: l3 is a value between l1 and l2, and the distance between the first and second meridians 70 and 72 is Cutting with a radius of curvature between the radius of curvature in one meridian direction and the radius of curvature in a second meridian direction,
The desired toric aspheric lens 68 can be manufactured.

That is, according to such a lens manufacturing method, it is possible to form lens surfaces having different curvatures from each other in the circumferential direction and the radial direction in the lens material 26. Of course, a toric lens 68 as shown in FIG.
A so-called bifocal lens 74 having a portion having two different radii of curvature (R1, R2) in one lens, as shown in FIG. 9, or shown in FIG. The lens center 76 and the optical axis center 78 are displaced by a predetermined dimension (l), and the curvature of the convex surface with respect to the lens center 76 gradually changes from R1 to Rn. The aspherical lens can be similarly cut and formed.

According to such a method, various aspherical lenses can be manufactured without bending the lens material 26 or changing the rotation center 16 of the lens material 26. A quality aspheric lens can be advantageously manufactured with excellent quality stability.

Further, in the manufacturing apparatus as described above, the bite support table 48 whose operation (turning operation) is gentler than the rotation operation of the rotating shaft 16 reciprocates in the approaching / separating direction with respect to the lens material 26. Since the radius of curvature of the cutting surface can be adjusted by moving the structure, the structure for reciprocating movement is compared with the conventional structure in which the rotating shaft that is rotated at high speed is reciprocated. Is simplified, the control is easy, and there is no problem in that the control accuracy is deteriorated due to the vibration around the axis due to the rotation.
And, therefore, according to such a manufacturing apparatus, the lens material
It is possible to raise the rotation speed of the rotating shaft 16 to a practical range where an economical cutting speed can be obtained, while ensuring sufficient cutting accuracy and stability for 26, thereby ensuring sufficient product quality. Therefore, it is possible to satisfy the economical efficiency while ensuring the above, and the practical use thereof can be advantageously achieved.

Furthermore, in the manufacturing apparatus according to the present embodiment, as a reciprocating position detecting means for detecting the reciprocating position of the cutting tool support 48, a first reciprocating position detecting device for directly detecting the operation amount of the reciprocating drive motor 50. 52, and a second reciprocating position detecting device 56 for directly detecting the moving amount of the bite support 48, and the moving amount of the bite support 48 based on the value detected by the first reciprocal position detecting device 52. Is determined, and the amount of movement of the bite support 48 can be feedback-controlled based on the value detected by the second reciprocating position detector 56. This has the effect that the movement control can be performed with an excellent response speed while ensuring high accuracy.

As mentioned above, although the Example of this invention was described in full detail, it is a literal illustration and this invention is not interpreted limited to only such a specific example.

For example, in the manufacturing apparatus of the embodiment, the turning center 42 of the cutting tool support 48 constituting the reciprocating unit 12 is closer to the reciprocating unit 12 than the contact position between the lens material 26 and the cutting bit 54. Was set to
It is also possible to set the center of rotation of 48 on the side of the rotational movement performing unit 10 with respect to the contact position between the lens material 26 and the cutting tool 54.

In addition to the motor, various driving mechanisms are used as the rotation driving means for driving the rotation member, the turning driving means for driving the turning tool, and the reciprocating driving means for driving the cutting tool reciprocally. For example, a piston mechanism or the like can be employed as the turning drive means, or a linear motor or the like can be employed as the reciprocating drive means.

In addition, the apparatus for manufacturing an aspheric lens according to the present invention is advantageously applied to manufacture aspheric lenses in various optical fields, in addition to ophthalmic lenses including contact lenses and intraocular lenses. Of course, it can be done.

In addition, although not enumerated one by one, the present invention can be practiced in modes in which various changes, modifications, improvements, and the like are added based on the knowledge of those skilled in the art. Both do not depart from the gist of the invention,
It goes without saying that they fall within the scope of the present invention.

[Brief description of the drawings]

FIG. 1 is an explanatory view schematically showing the configuration of a specific example of an apparatus for manufacturing an aspheric lens according to the present invention. FIG. 2 is a partially cutaway perspective view for explaining a rotation angle detecting device which is advantageously applied to the manufacturing device of the aspherical lens shown in FIG. 1, and FIG. FIG. 4 is an explanatory diagram for explaining the operation principle of the rotation angle detection device. FIG. 4 is a perspective view for explaining a reciprocating position detecting means which is advantageously applied to the aspherical lens manufacturing apparatus shown in FIG. Furthermore, FIG.
It is a model figure for demonstrating the cutting process of the lens by the manufacturing apparatus of the aspherical lens shown in the figure. FIG. 6 is a block diagram for explaining a control method of the reciprocating drive means in the manufacturing apparatus of the aspherical lens shown in FIG. 7 is a perspective view showing a toric lens which can be advantageously manufactured by the aspherical lens manufacturing apparatus shown in FIG. 1, and FIGS. 8 (a) to 8 (e) are perspective views. FIGS. 4A and 4B are explanatory diagrams schematically showing a cutting process for manufacturing such a toric lens. FIGS. 9 and FIG. 10 correspond to FIG.
FIG. 9 is a view showing another specific example of an aspherical lens that can be advantageously manufactured by the manufacturing apparatus of the aspherical lens shown in the figure, and FIG. 9 is a perspective view showing a bifocal-shaped aspherical lens. FIG. 10 is a side view showing a prism-shaped aspherical lens. 10: Rotational movement execution unit, 12: Reciprocation movement execution unit 14: Rotation center, 16: Rotation axis 18: Rotation drive motor, 24: Chuck 26: Lens material, 28: Rotation angle detector 40: Swivel table, 42: Swivel Center 44: Revolving drive motor, 46: Revolving angle detector 48: Tool holder, 50: Reciprocating drive motor 52: First reciprocating position detector 53: Tool holder, 54: Cutting tool 56: Second reciprocating position Detector 64: Reciprocating drive motor controller 66: External input device 68: Aspheric lens (toric shape) 74: Aspheric lens (bifocal shape) 80: Aspheric lens (prism shape)

Claims (2)

(57) [Claims] 1. A predetermined cutting tool is brought into contact with the lens material while rotating the predetermined lens material about one axis, and is pivotally moved about one axis orthogonal to the rotation axis of the lens material. By letting such a lens material, in each part in the circumferential direction and the radial direction thereof, be cut with a radius of curvature different from each other, an apparatus for manufacturing an aspheric lens having a desired aspheric shape, A rotation member rotatably supported so that the lens material can rotate around one axis, a rotation driving means for rotating the rotation member, and a rotation angle of the rotation member. Rotation angle detecting means for detecting the rotation of the rotating member, the cutting bit is arranged to face the holder of the rotating member, and cuts the lens material held by the holder A tool supporting member to be rotatable about one axis orthogonal to the rotation axis of the rotating member, and to be reciprocally movable in the approaching / separating direction with respect to the lens material; and rotating the tool supporting member. Turning drive means for driving; turning angle detection means for detecting a turning angle of the bite support member; reciprocal drive means for driving the bite support member to reciprocate; and a reciprocating position for detecting a position of the bite support member in a reciprocating direction. Detecting means, and supporting the bite support by a predetermined amount corresponding to the turning angle of the bite supporting member detected by the turning angle detecting means in synchronization with the rotation angle of the rotating member detected by the rotation angle detecting means. Control means for controlling the reciprocating drive means so that the member can be reciprocated; and The control means, comprising: first reciprocating position detecting means for directly detecting an operation amount of the reciprocating driving means; and second reciprocating position detecting means for directly detecting a moving amount of the bite supporting member. In the above, based on a detection signal by the first reciprocating position detecting means, according to the turning angle of the cutting tool support member detected by the turning angle detecting means,
Manufacturing the aspherical lens, wherein the amount of operation of the reciprocating drive means is determined, and the amount of operation of the reciprocal drive means is feedback-controlled based on a detection signal from the second reciprocating position detecting means. apparatus. 2. The aspherical lens manufacturing apparatus according to claim 1, wherein said reciprocating drive means linearly reciprocates the cutting tool support member.